I use whatever happens to be near my chair with a large enough eye that I can see to thread it. If the one I pick up doesn't seem to work right I try another one. I've never looked at the size or brand in my entire life. Just use the one that fits your hand and does what you want it to do. My mother had rather delicate tips on her fingers and liked a small needle. I have wide square tipped washer woman hands and fingers, I need a longer needle.